What can be done about older 030 NeXT cubes that have a fan that turns in the “wrong” direction?
fan, running wrong The fan on older 030 NeXTs cubes sucks air out of the back of the cube which means that it draws unfiltered air in through the optical disk on the front of the cube. This causes optical disks to succumb to dust must sooner than cubes with the new-style fan which turns in the opposite direction. NeXT has apparently reversed their decision regarding fan reversal in the case of machines that have been upgraded to 040 processor boards. It is now considered okay to reverse the direction of fans in these machines. If you have many third-party cards installed in your cube or an older processor board, you may wish to consider not reversing fan direction (overheating could become a problem). In any case, do not reverse the fan’s polarity, only reverse the fan assembly itself. Perhaps the best solution is obtain the cleaning kit and OD filter from NeXT.
fan, running wrong The fan on older 030 NeXTs cubes sucks air out of the back of the cube which means that it draws unfiltered air in through the optical disk on the front of the cube. This causes optical disks to succumb to dust must sooner than cubes with the new-style fan which turns in the opposite direction. NeXT has apparently reversed their decision regarding fan reversal in the case of machines that have been upgraded to 040 processor boards. It is now considered okay to reverse the direction of fans in these machines. If you have many third-party cards installed in your cube or an older processor board, you may wish to consider not reversing fan direction (overheating could become a problem). In any case, do not reverse the fan’s polarity, only reverse the fan assembly itself. Perhaps the best solution is obtain the cleaning kit and OD filter from NeXT.